kernel/syscall/ioctl.c

   1 /*
   2  * CDDL HEADER START
   3  *
   4  * The contents of this file are subject to the terms of the
   5  * Common Development and Distribution License (the "License").
   6  * You may not use this file except in compliance with the License.
   7  *
   8  * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
   9  * or http://www.opensolaris.org/os/licensing.
  10  * See the License for the specific language governing permissions
  11  * and limitations under the License.
  12  *
  13  * When distributing Covered Code, include this CDDL HEADER in each
  14  * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
  15  * If applicable, add the following below this CDDL HEADER, with the
  16  * fields enclosed by brackets "[]" replaced with your own identifying
  17  * information: Portions Copyright [yyyy] [name of copyright owner]
  18  *
  19  * CDDL HEADER END
  20  */
  21 /*
  22  * Copyright 2007 Sun Microsystems, Inc.  All rights reserved.
  23  * Use is subject to license terms.
  24  */
  25
  26 /*      Copyright (c) 1983, 1984, 1985, 1986, 1987, 1988, 1989 AT&T     */
  27 /*        All Rights Reserved   */
  28
  29 /*
  30  * Portions of this source code were derived from Berkeley 4.3 BSD
  31  * under license from the Regents of the University of California.
  32  */
  33
  34 #pragma ident   "%Z%%M% %I%     %E% SMI"
  35
  36 #include <sys/param.h>
  37 #include <sys/isa_defs.h>
  38 #include <sys/types.h>
  39 #include <sys/sysmacros.h>
  40 #include <sys/cred.h>
  41 #include <sys/systm.h>
  42 #include <sys/errno.h>
  43 #include <sys/ttold.h>
  44 #include <sys/vnode.h>
  45 #include <sys/file.h>
  46 #include <sys/mode.h>
  47 #include <sys/proc.h>
  48 #include <sys/uio.h>
  49 #include <sys/kmem.h>
  50 #include <sys/filio.h>
  51 #include <sys/sunddi.h>
  52 #include <sys/debug.h>
  53 #include <sys/int_limits.h>
  54 #include <sys/model.h>
  55
  56 /*
  57  * I/O control.
  58  */
  59
  60 int
  61 ioctl(int fdes, int cmd, intptr_t arg)
  62 {
  63         file_t *fp;
  64         int error = 0;
  65         vnode_t *vp;
  66         struct vattr vattr;
  67         int32_t flag;
  68         int rv = 0;
  69
  70         if ((fp = getf(fdes)) == NULL)
  71                 return (set_errno(EBADF));
  72         vp = fp->f_vnode;
  73
  74         if (vp->v_type == VREG || vp->v_type == VDIR) {
  75                 /*
  76                  * Handle these two ioctls for regular files and
  77                  * directories.  All others will usually be failed
  78                  * with ENOTTY by the VFS-dependent code.  System V
  79                  * always failed all ioctls on regular files, but SunOS
  80                  * supported these.
  81                  */
  82                 switch (cmd) {
  83                 case FIONREAD: {
  84                         /*
  85                          * offset is int32_t because that is what FIONREAD
  86                          * is defined in terms of.  We cap at INT_MAX as in
  87                          * other cases for this ioctl.
  88                          */
  89                         int32_t offset;
  90
  91                         vattr.va_mask = AT_SIZE;
  92                         error = fop_getattr(vp, &vattr, 0, fp->f_cred, NULL);
  93                         if (error) {
  94                                 releasef(fdes);
  95                                 return (set_errno(error));
  96                         }
  97                         offset = MIN(vattr.va_size - fp->f_offset, INT_MAX);
  98                         if (copyout(&offset, (caddr_t)arg, sizeof (offset))) {
  99                                 releasef(fdes);
 100                                 return (set_errno(EFAULT));
 101                         }
 102                         releasef(fdes);
 103                         return (0);
 104                         }
 105
 106                 case FIONBIO:
 107                         if (copyin((caddr_t)arg, &flag, sizeof (flag))) {
 108                                 releasef(fdes);
 109                                 return (set_errno(EFAULT));
 110                         }
 111                         mutex_enter(&fp->f_tlock);
 112                         if (flag)
 113                                 fp->f_flag |= FNDELAY;
 114                         else
 115                                 fp->f_flag &= ~FNDELAY;
 116                         mutex_exit(&fp->f_tlock);
 117                         releasef(fdes);
 118                         return (0);
 119
 120                 default:
 121                         break;
 122                 }
 123         }
 124
 125         /*
 126          * ioctl() now passes in the model information in some high bits.
 127          *
 128          * FIXME: This is a terrible hack to preserve the original behavior
 129          * before we combined f_flag and f_flag2 into a single field.  The
 130          * proper fix would be to pass the file_t pointer to the fop_ioctl
 131          * function instead of the vnode.  The data model could be passed in
 132          * by itself.  (get_udatamodel uses curproc so we can't push it into
 133          * the individual ioctl functions or we'd break kernel-issued
 134          * ioctls.)
 135          */
 136         flag = (fp->f_flag & 0xffff) | get_udatamodel();
 137         error = fop_ioctl(fp->f_vnode, cmd, arg, flag, CRED(), &rv, NULL);
 138         if (error != 0) {
 139                 releasef(fdes);
 140                 return (set_errno(error));
 141         }
 142         switch (cmd) {
 143         case FIONBIO:
 144                 if (copyin((caddr_t)arg, &flag, sizeof (flag))) {
 145                         releasef(fdes);
 146                         return (set_errno(EFAULT));
 147                 }
 148                 mutex_enter(&fp->f_tlock);
 149                 if (flag)
 150                         fp->f_flag |= FNDELAY;
 151                 else
 152                         fp->f_flag &= ~FNDELAY;
 153                 mutex_exit(&fp->f_tlock);
 154                 break;
 155
 156         default:
 157                 break;
 158         }
 159         releasef(fdes);
 160         return (rv);
 161 }
 162
 163 /*
 164  * Old stty and gtty.  (Still.)
 165  */
 166 int
 167 stty(int fdes, intptr_t arg)
 168 {
 169         return (ioctl(fdes, TIOCSETP, arg));
 170 }
 171
 172 int
 173 gtty(int fdes, intptr_t arg)
 174 {
 175         return (ioctl(fdes, TIOCGETP, arg));
 176 }